Steam-boiler.



No. 760,520. PATENTED MAY 24, 1904.

STEAM BOILER.

APILIOATION FILED JAN. 21, 1904.

N0 MODEL. 2 SHEETS-SHEET 1.

INVENTOR PETERS c6, PHOTO-LWHD. WASHINGTON, uv c.

No. 760,520. PATENTED MAY 24, 1904. A. CAMPBELL.

STEAM BOILER.

APPLICATION FILED JAN. 21, 1904.

N0 MODEL. 2 SHEETS-SHEET 2.

IIIIIIIIIIIIIIIIII INVENTUR Patented May 24, 1904.

UNITED STATES PATENT OFFICE.

, ALEXANDER CAMPBELL, OF QTTAWA, CANADA.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 760,520, dated May 24, 1904.

Application filed January 21, 1904. Serial No. 190,086. (No mcdelfl To all whmn it may concern/.3

Be it known that I, ALEXANDER CAMPBELL, mechanical engineer, of the city of Ottawa, in the county of Carleton, in the Province of Ontario, Canada, have invented certain new and useful Improvements'in Steam-Boilers; and I do hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to improvements in boilers of the drop-tube type; and the objects of my improvements are, first, to provide a more compact fire-box; second, to permit of the tubes in the crown-sheet being expanded therein; third, to increase the heating-surface; fourth, to permit gusset or other staying for the heads instead of the rod-stay; fifth, more rapid circulation.

Heretofore the crown-sheet having the tubes depending therefrom was constructed with construction. In the present boiler the top tubes may be expanded, if desired, or secured by being screwed into thecrown-sheet. Another disadvantage of the former boiler was the use of stay-rods to secure the heads or end sheets. These rods on account of their great length bent under theirown Weight, affording little if any support to the headsheets. In the present boiler gusset or other stays may be used to secure the heads, the manhole affording access for this purpose, and the fire-box may he stayed to the outer shell by crow-feet,girders, gusset, or other type of stays instead of stay-bolts. The types of stays shown are preferred, as by removing the pins from the top and bottom the stays are readily removable, giving more V The tubes also had to be screwed mto place, necess tat ng a large extra cost onrows of tubes to secure the stays to the crownsheet. 1 preferably secure T-irons in the spaces riveted to the crown sheet and having openings in the web to hold the pins securing the stays. The horizontal or side tubes give a large heating-surface heretofore not utilized, and as they alternate from each side sheet of the lire-box add materially to the efliciency. The drop-tubes from the crown or tube sheet being on an angle afford rapid circulation and being self-supporting avoid the use of cast-iron caps or ends. The length of vertical drop-tubes is limited and varies with the diameter of the tubes, for the reason that the fire impinging on the closed end of the tube creates a gas or steam bubble which in expanding under the action of the heat forces the water away from direct contact with the tube end until its force overcomes the weight of the water above it, when it escapes through the tube into the steam-space, allowing the water once more to come in contact with the hot end of the tubes. The longer thetube the hotter the end gets and the more frequently it burns o'li', allowing the water to escape into the fire and causing great delay. When the tubes are inclined, the ire impinges against the under side for the whole length of the tube, and the steam-bubbles rise from the parts and making it impossible to burn the ends off. By feeding the water into the bottom of the boiler it begins to be broken up by the action of the fire on the side sheets and by the time it reaches the top tubes is near the boiling-point. Hence sediment will be dropped to the bottom of the boiler, whence it is removed through hand-holes.

With these objects in view and to the end of realizing other advantages hereinafter appearing my invention consists in certain features of construction and combination of parts hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure 1 is an end View of the boiler with the heads re- 100 moved, showing the interior construction. Fig. 2 is a sectional view showing arrange ment of inclined, corresponding, and horizontal tubes. Fig. 3 is a top plan view of the crown-sheet, showing the spacings, T-irons for stays, and relative positions of the droptubes.

Similar letters refer to similar parts throughout the severalviews.

The boiler illustrated in the drawings comprises an outer shell A and an inner shell or fire-box B, having the crown-sheet C formed with sides 0 and C inclined at right angles to one another, the apex being rounded.

D and D indicate the sides of the fire-box.

E indicates the grate-bars, suitably supported.

The sides of the fire-box B are securely stayed to the outer shell by stay-bolts F, and the crown-sheet is stayed by the stays 0, secured to the T-iron's riveted on the crownsheet between the adjacent rows of tubes (see Fig. 3) and by pins G inserted through an gle-irons Gr, riveted to the exterior shell, the said pins passing through an eye formed in the end of the stay and secured therein by cotters G3. The stays L are secured to the rounded apex of the crown-sheet and to angu lar'irons riveted back to back on the outer shell and are removably held therein by pins. The flat surfaces of the heads are secured to the outer shell by means of gusset or other stays. (Not herein shown.) a

The manhole H gives access to the space between the fire-box and outer shell,-and the inclination of the stays G G affords ample space on the top of the crown-sheet for repairs, inspection, &c., or removing the pins holding the stays any number of them may be temporarily removed, affording lots of Working space.

The tubes T are secured to the side C" of the crown sheet and extended at approximately right angles thereto, and the tubes T are similarly secured to the crown-sheet C the tube-holes T in the crown-sheet 0 being spaced apart to allow the tubes T secured in the holes T of the crown or tube sheet C to'extend across between the adjacent rows of thetubes T. (See Fig. 3.)

In Fig. 3 I have shown some of the tubes secured in place and extending between the opposite adjacent rows.

- The tubes T extend from right to left, and the tubes T incline from left to right, each row of tubes T alternating with a row of tubes T and these horizontal tubes extend 5 to within a short distance of the inclined tubes, affording a large heating-surface. The horizontal tubes being in alinement with the inclined tubes will also alternatez'. 0., the tubes T will extend between two adjacent verticalrows of tubes T The side tubes may be slightly inclined, and these, as well as the other tubes, may be provided with circulators (not shown) of any desired kind.

The top of the crownsheetthat is, the juncture of the sides G and C is preferably rounded.

The space between the inner and outer shells forms the water and steam space, and the arrows'in Fig. 2 indicate the circulating currents of the water.

The ends of the inclined and horizontal tubes which project into the fire-box or inner shell are closed, and the ends which are secured in the top and side tube sheets are open to the water in the space between the shells.

The customary inlet and outlets are provided, as well as cleaning-out holes in the lower parts of the heads between the shells.

In setting the boiler a sheet-iron or expanded-metal casing lined inside and out with a non-conductor, as asbestos plaster, is secured to each side and extends vertically over the greater part of the side; This forms smokeconducting chambers and also increases the heating-surface as the return draft comes in direct contact with the outer shell. These chambers are suitably connected at the rear end and at the front end to a saddle or breeching and thence to the stack, and byproviding cast-iron bases the boiler is self-contained and may be used as a portable boiler.

I do not Wish to limit myself to the form of crown-sheet shown and described, as all modifications, such as a crown-sheet having the sides converging from 'the top downward that is, in the shape of a V instead of an inverted V, as shown would fall within the spirit and scope of my invention, and also slightly rounding the sides of the tube-sheet or forming the tubesh'eet in the shape of a W or an inverted W. I am also aware that by shortening the top set of inclined tubes and putting a fireproof partition between them and the horizontal ones, leaving a space at the rear of the partition, return draft may be obtained; but as this is old I do not make claim thereto.

I claim- 1. In a boiler of the class described, in combination with the outer shell an inner'shell spaced therefrom having its top formed of an angled tube-sheet and drop-tubes depending from said sheet substantially as described.

2. In a boiler in combination with the outer shell an inner shell spaced therefrom having its top formed in the shape of an inverted V drop-tubes depending from the sides of said top at an angle of substantially ninety degrees with the said sides substantially as described.

3. In a boiler of the class described in combination with the outer shell an inner shell spaced therefrom having its bottom and sides substantially parallel with the top and sides of the outer shell, said inner shell having its top formed of .an angled tube-sheet and droptubes depending therefrom substantially as described.

4. In a boiler of the class described in combination with the outer shell an inner shell spaced therefrom having its bottom and sides substantially parallel with the bottom and sides of the outer shell and a top formed in the shape of an inverted V, drop-tubes depending from the sides of said top at a right angle therewith substantially as described.

5., In a boiler of the class described, in combination with the outer shell an inner shell spaced therefrom having its bottom and sides substantially parallel with the bottom and sides o'l said outer shell, and having an angledtop or tube sheet, drop-tubes depending from the sides of said top at a right angle thereto, and

horizontal tubes projecting from the sides of said inner shell substantially as described.

6. In a boiler in combination with the outer shell an inner shell spaced therefrom having its bottom and sides substantially parallel with the bottom and sides of the outer shell and having a top formed of an angled tube-sheet, drop-tubes depending from the sides of said top at a right angle thereto, and horizontal tubes projecting from the sides of said inner shell substantially as described.

7. In a boiler of the class described in com-- bination with the outer shell an inner shell spaced therefrom having its bottom and sides substantially parallel with the bottom and sides of said outer shell, and a top formed in the shape of an inverted V, drop-tubes depending from .the sides of said top at a right angle thereto, and horizontal tubes projecting from the sides of said inner shell substantially as described.

8. In a boiler of the class described the combination with the outer shell of an inner shell spaced therefrom having its bottom and sides substantially parallel with the bottom and sides of said outer shell, and having a top formed of an angled tube-sheet, drop-tubes depending from said tube-sheet, said tubes having closed inner ends and their outer ends opening into the space between the outer and inner shells horizontal tubes projecting from the sides of said inner shell, said tubes having closed in ner ends and their outer ends opening into the space between the outer and inner shells substantially as described. a

9. In a boiler of the class described the combination with the outer shell of an inner shell spaced therefrom having its bottom and sides substantially parallel with the bottom and sides of the outer shell, and a top formed in the shape 01" an inverted V, drop-tubes depending from the sides of said top at a right angle thereto said tubes having their inner ends closed and their outer ends opening into the space between the outer and inner shells, horizontal tubes projecting from the. sides or said inner shell, said tubes having closed inner ends and their outer ends opening into the space between the outer and inner shells substantially as described.

10. In a boiler of the class described the combination with the outer shell of an inner shell spaced therefrom so as to form between them a water and steam compartment, said in ner shell having its bottom and sides substantially parallel with the bottom and sides of the outer shell and a crown-sheet, having sides forming an angle of substantially ninetydegrees diverging from the top downward and extended to connect with the sides of the inner shell; water-tubes projecting from the sides of said crown-sheet at a right angle thereto and extending downwardly; horizontal tubes projecting from the sides of said inner shell and extending inwardly; a lire-box in the lower part of the'front end of the inner shell substantially as described.

11. In a boiler of the class described the combination with the outer shell, of an inner shell spaced therefrom so as to form between them a water and steam compartment; said inner shell having substantially vertical sides, and a crown-sheet having sides tormmg an angle substantially ninety degrees said sides diverging from the top downward and extending to connect with the sides of the inner shell; water-tubes projecting from the sides of said crown-sheet at a right. angle thereto and extending downwardly, said tubes having closed inner ends and their outer ends opening into the water and steam compartment, horizontal Water-tubes projecting from the sides of the inner shell and extending in wardly, said tubes having closed inner ends and their outer ends opening into the water and steam compartment substantially as described.

12. In a boiler of the class described, in combination, an outer shell, an inner shell spaced from said outer shell so as to form between them a water and steam compartment; the inner shell comprising a bottom and sides substantially parallel with the bottom and sides of the outer shell, and a crown-sheet formed in the shape of an inverted Vwhose sides diverge at an angle of substantially ninety degrees and are connected to the sides of said inner shell; a fire-box in the lower part of the front end of the inner shell, water-tubes projecting from the sides'oi the crown-sheet at a right angle thereto, said tubes having closed inner ends and open outer ends, and terminating at their inner ends in the space above and back of the [ire-box, horizontal water-tubes IIO projecting from the sides of said inner shell, said tubes having closed inner ends and open outer ends, and terminating at theirinner ends in the space above and back of the fire-box, substantially as described.

13. In a boiler of the class described, in combination, an outer shell, an inner shell spaced therefrom so as to form between them a water and steam compartment; the inner shell comprising a bottom and substantially vertical sides, and a crown-sheet angled in the shape of an inverted v with its sides diverging at an angle of substantially ninety degrees to meet the sides of said inner shell, the whole forming a fire-compartment; series of watertubes depending from the sides of the crownsheet at a right angle thereto, said tubes extending downward and terminating into the spacein the fire-compartment, said tubes having their inner ends closed and their outer ends opening into the water and steam compartment; horizontal tubes projecting from the sides of said inner shell, said tubes extending inward and terminating into the firecompartment, said tubes having their inner ends closed and their outer ends opening into the water and steam compartment, substantially as described.

14. In aboiler of the class described, in combination with the outer shell, an inner shell spaced therefrom having its top formed of an angled tube-sheet and series of drop-tubes depending from said tube-sheet in a direction inclined relatively to a horizontal cross-section of the boiler, substantially as described.

15. In aboiler of the class described in combination with the outer shell, an inner shell spaced therefrom having its top formed in the shape of an inverted V, series of drop-tubes depending from each of the sides of said top at an angle of substantially ninety degrees with the said sides the series on one side alternating with the series on the other side substantially as described.

16. In a boiler of the class described in combination with the outer shell, an inner shell spaced therefrom having its bottom and sides substantially parallel with the bottom and sides of the outer shell; said inner shell having a crown-sheet formed in the shape of an inverted V, series of drop-tubes dependingfrom each of the sides of the crown'sheet at a right angle thereto, the series of one side alternating with the series of the other side, series of horizontal tubes projecting from the sides of the inner shell, the series on one side alternating with the series on the other side and each series on one side of the shell corresponding with the series above same in the crownsheet, substantially as described.

17. In a boiler of the class described, in combination, an outer shell and an inner shell spaced therefrom forming between them a water and steam compartment; the inner shell comprising a bottom and substantially vertical sides, and a crown-sheet formed with its sides at an angle of substantially ninety degrees and diverging from the top downward and outward to meet the sides of said inner shell, the whole forming a fire-compartment; series of water-tubes depending from each side of the crown-sheet at a right angle thereto and extending downward and terminating into the fire-compartment, said tubes having their in- .ner ends closed and their outer ends in open communication with the water and steam compartment, the series on one side of the crownsheetalternating with the series on the other side; horizontal tubes projecting from each vertical side of the inner shell and extending inward and terminating in the fire-compartment, said tubes having their inner ends closed and their outer ends in open communication with the water and steam compartment, the series on one side of the shell alternating with the series on the other side of said shell and the series on each of the vertical sides of the shell being in vertical alinement with the series above in the corresponding side of the crown-sheet, substantially as described.

In testimony whereof I sign this specification, in the presence of two witnesses, this 19th day of December, 1903, at Ottawa.

ALEXANDER CAMPBELL.

\Vitnesses:

GHAs. L. RICHARD, WV. J. WVrrHRow. 

